help me? 1

[dho]

mil-c-5541E only specifies class, while mil-dtl-5541F added type I and II. type II says no hexavalent chrome.
if type II is due to RoHS, is the chem coated aluminum part per type I hazardous or just the chemical (solution)used in the process? we forgot to specify type II and the customer is giving us hard time.
thanks.

 

[dho]

Is the type I coated layer contain hexavalent chrome? if yes, is it a free state? or reacted with aluminum? if reacted with aluminum, what is the result compound? is that compound toxic and subject to RoHS?

 

[TVP]

Yes, Type I coatings contain hexavalent chromium. There are free (leachable) hexavalent chromium ions in the conversion coating. Here is a link to one publication that discusses concentration of hexavalent chromium within a chromate conversion coating deposited onto aluminum:

http://www.chem.ualberta.ca/~mccreery/RLM publication PDFs/mccreery151.pdf

 

[dho]

thanks, TVP.

 

[dho]

is iridite 14-2 hexavalent chrome free?
thanks.

 

[OGMetEngr]

Also if any cutting, welding occurs hex chrome may be inhaled.

 

[arunmrao]

@ dho

A good title , will invite good response. Do not continue your next thread Help 3. It is not professional.

I'm just one step away from being rich, all I need now is money.
( read somewhere on the internet)

 

[tbuelna]

dho-

If your customer is rejecting these parts because they might have used a chem film process using hexavalent chrome, then either you did not follow their instructions, or they did not provide specific instructions to you. In our modern world, it is often a requirement for components delivered to an OEM that they comply with strict environmental regulations at every step along the way. Such as no cadmium, no lead, no beryllium, or no hexavalent chrome.